.helppage {
    color: white;
    background-color: black;
    max-width: 480px;
    margin: 0 auto;
    padding: 15px;
}
img, video {
    max-width: calc(100% - 30px);
    width: 100%;
    height: auto;
    margin: 15px 0;
}
a {
    color: #147EFF;
}